The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the invention. Some such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.
A wireless communication network refers to a communications network that provides radio signal coverage over a geographical area. Examples of such networks are for example UMTS (Universal Mobile Telecommunications System), GSM (Global System for Mobile Communications) or WiMAX (Worldwide Interoperability for Microwave Access), wherein radio signal coverage is provided through base stations. In general the base stations connect through a backhaul connection to a gateway, such as in WiMAX, or some other central node in the network, such as BSC (base station controller) or RNC (radio network controller). Thus, the central node, for example, and the connections from the base stations to the central node, have to have enough capacity to handle the traffic introduced by the base stations.
In 3GPP (3rd Generation Partnership Project) work is being done on the evolution of the existing UMTS standards, under the name of LTE (Long Term Evolution). In LTE the air-interface part of the network is being defined as E-UTRAN (Evolved Universal Terrestrial Radio Access). The base stations in LTE are called the eNBs (Evolved UTRAN NodeBs) which connect to MME (Mobility Management Entity) and S-GW (Serving Gateway) in the core network through S1 logical interface. The MME handles the control plane and S-GW handles the user plane traffic processing and they may reside in the same network node. The eNBs are connected to each other through an X2 logical interface. In E-UTRAN the eNBs provide radio signal coverage which is used by the user equipment to connect to the network.
To improve the quality of the connections and fill gaps in the radio signal coverage in wireless communication networks, such as those mentioned above, the coverage of the network can be extended and complemented by adding base stations. In a scenario of LTE E-UTRAN being worked on in 3GPP, radio signal coverage of a wireless network is extended to provide signal coverage in homes with Home NodeBs (HNBs), as described in 3GPP TR R3.020 v.0.0.2 (2007-04).
In such a scenario, the overall number of base stations including, eNBs and HNBs, becomes very large. In order for each base station, eNB or HNB, to have S1 connection with MME/S-GW, the MME/S-GW need to have increased traffic handling capability and processing power. Even though the subscriber traffic from the HNBs would be small, the number of HNBs may require increased capacity from the MME/S-GW in order to control and manage the HNBs and user equipment connected through the HNBs to the network—thus on the control plane.
The large number of deployed base stations, as increased by the HNB scenario in a wireless communications network, introduces a scalability problem to the higher level network nodes, such as MME and S-GW in the case of 3GPP LTE.